web/vegpath/util.php: Added array_non_empty(), join_non_empty()

web/vegpath/index.php: add_ref(): redirect: Don't display "Loading" as the page itself is not shown to the user when using a Location: header

web/vegpath/index.php: URL fragment redirect: Fixed bug where can't prefix the fragment with / because this won't work if VegPath is not at the top-level of the domain (and in any case is unnecessary to form a relative path)

web/vegpath/index.php: URL fragment redirect: Blink the namespace being loaded, rather than displaying "Loading" at the bottom of the page, to make it clearer what's being loaded

web/vegpath/index.php: add_ref(): Don't display the URL pattern in monospace, because fixed-width font is not needed and variable-width font is easier to read. This requires decreasing the header level because variable-width font is bigger than fixed-width font.

web/vegpath/main.css: Added entries for h6

web/vegpath/index.php: parse_dot_path() calls: Fixed bug where need to test result components using \`!== ""\` instead of just using the value as a boolean because PHP incorrectly interprets the string "0" as false

web/vegpath/util.php: Path: Made $tail default to ""

web/vegpath/index.php: URL fragment redirect: Prepend / instead of ? because filesystem paths are now redirected using .htaccess, removing the need to set the query string

web/vegpath/index.php: phpMyAdmin(): Fixed bug where can't use tbl_alter as the column target page because it requires a token param, which is only obtained after the user logs in